1. Field of the Invention
The present invention relates to hand trucks, and more particularly, to an arrangement of a retractable third leg thereof wherein the third leg is positively locked in a deployed position, and is manually released therefrom to enable collapsed stowage of the hand truck.
2. Description of the Prior Art
U.S. Pat. No. 3,064,990, issued to Anthony R. Salvucci on Nov. 20, 1962, discloses a retractable gas cylinder cart wherein a strut extends from the front axle, engaging a loop formed in a tab attached to the retractable third leg. This invention provides a simple overcenter mutual engagement between strut and tab, and components are held in place solely by gravity. Like the present invention, a rod member of the strut passes through the loop, enabling the strut to assume a progressively more vertical position when the third leg is collapsed, or folded. However, construction of the '990 device differs from that of the present invention, and specifically fails to provide two points of interfering engagement, as found in the present invention, which contribute to secured extension of the third leg.
U.S. Pat. Nos. 3,578,353 and 4,630,837, issued respectively to Robert J. Lockhart on May 11, 1971, and to Eugene A. Kazmark on Dec. 23, 1986, exemplify the use of notched brackets engaging struts to secure a retractable leg in a deployed position. These inventions also lack the two points of interfering engagement mentioned above.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.